Chemistry Commons^™

Investigation Of Immobilized Enzymes In Confined Environment Of Mesoporous Host Matrices, Xiaoliang Wang

USF Tampa Graduate Theses and Dissertations

Enzyme immobilization in metal-organic frameworks (MOFs) as a promising strategy, is attracting the interest of scientists from different disciplines with the expansion of MOF’s development. Different from other traditional host materials, their unique strengths of high surface areas, large yet adjustable pore sizes, functionalizable pore walls, and diverse architectures make MOFs an ideal platform to investigate hosted enzymes, which is critical to the industrial and commercial process. In addition to the protective function of MOFs, the extensive roles of MOFs in the enzyme immobilization are being well-explored by making full use of their remarkable properties like well-defined structure, high porosity, …

Investigating Thermodynamics And Kinetics Of Methylene Blue And Eriochrome Black-T Adsorption On Activated Carbon Prepared From Coconut Husk, Abdul Rahman Wahoud, Lotfi Abdul Samed Bawazer

Hadhramout University Journal of Natural & Applied Sciences

In this research, the adsorption process was studied for methylene blue eriochrome black-T from aqueous solutions on the surface of activated carbon prepared from coconut husk by chemical activation with potassium hydroxide. The results show that the adsorption isotherm for methylene blue follows the Langmuir model while it follows the Freundlich model and the maximum adsorption capacity was 909 mg/g for methylene blue and 262 mg/g for eriochrome black-T. The equilibrium contact time reached in about 90 minutes at lower concentrations and 120 minutes at higher concentrations. Two simplified kinetic models including pseudo-first-order and pseudo-second-order equations were selected to follow …

Kinetic, Equilibrium And Application Studies For Removal Of Methylene Blue From Aqueous Solution Using Sesbenia Dates Activated Carbon, Mohammed Saleh Bashanaini, Gameel Ahmed Baghaffar, Waheeb Abdellah Bin Frejan

Hadhramout University Journal of Natural & Applied Sciences

In the present work, sesbenia dates as local agricultural waste has been successfully used for the preparation of activated carbon (AC) by sulphuric acid. This sulphuric acid based activated carbon (SD) and (MSACS) were used for the removal of one cationic dye viz., methylene blue (MB) from aqueous solutions. The structure and physical and chemical properties of (SD) and (MSACS) are investigated using (FTIR) and (SEM) analysis and pH surface and Boehm titration. The effect of the differential experimental parameters controlling the adsorption of dye onto (SD) and (MSACS), were thoroughly investigated, such as the effect of pH, initial dye …

Electro-Organic Synthesis Of Schiff-Bases And Azo-Schiff Bases By Electrochemical Reduction Of The Nitro Group Group In Different Media, Siba Naseef, Deep Bakair, Rushdi Mador

Hadhramout University Journal of Natural & Applied Sciences

In this research synthesized amino is derivative of Schiff-bases by using electrolysis cell. Electrochemical reduction of para-nitroaniline and electrocatalysed condensation have been carried out at zinc electrode and anode from coal in the presence of potassium chloride as supporting electrolyte in water/methanol solution, and in the application of 20V voltage, where interaction is in two stages: the first stage involves the electrochemical reduction of nitro group and get the amino and the second phase also, azo Schiff was synthesized between para-nitroaniline and metoxybenzealdehyde by electrolysis method, which was supplied with a zinc electrode as cathode to perform electrochemical reduction in …

The Primarily Undergraduate Nanomaterials Cooperative: A New Model For Supporting Collaborative Research At Small Institutions On A National Scale, Steven M. Huges, Mark P. Hendricks, Katherine M. Mullaugh, Mary E. Anderson, Anne K. Bently, Justin G. Clar, Clyde A. Daly Jr., Mark D. Ellison, Z. Vivian Feng, Natalia I. Gonzalex-Pech, Leslie S. Hamachi, Christine L. Heinecke, Joseph D. Keene, Adam M. Maley, Andrea M. Munro, Peter N. Njoki, Jacob H. Olshansky, Katherine E. Plass, Kathryn R. Riley, Matthew D. Sonntag, Sarah K. St. Angelo, Lucas B. Thompson, Emily J. Tollefson, Lauren E. Toote, Korin E. Wheeler

Chemistry Faculty Publications

The Primarily Undergraduate Nanomaterials Cooperative (PUNC) is an organization for research-active faculty studying nanomaterials at Primarily Undergraduate Institutions (PUIs), where undergraduate teaching and research go hand-in-hand. In this perspective, we outline the differences in maintaining an active research group at a PUI compared to an R1 institution. We also discuss the work of PUNC, which focuses on community building, instrument sharing, and facilitating new collaborations. Currently consisting of 37 members from across the United States, PUNC has created an online community consisting of its Web site (nanocooperative.org), a weekly online summer group meeting program for faculty and students, …

Using Covalent Modifications To Distinguish Protein Electrospray Mechanisms: Charged Residue Model (Crm) Vs. Chain Ejection Model (Cem), Lars Konermann, Douglas J. D. Pimlott

Chemistry Publications

Different mechanisms have been proposed for the formation of gaseous protein ions during electrospray ionization (ESI). In the charged residue model (CRM) ions are produced upon nanodroplet evaporation to dryness. This mechanism is thought to dominate in native ESI, where proteins retain compact conformations, with charge states close to the Rayleigh charge of protein-sized aqueous droplets. Much higher charge states are generated from proteins that are unfolded in solution. The chain ejection model (CEM) has been proposed for ESI under such denaturing conditions. In the CEM proteins are gradually expelled, while mobile H⁺ equilibrate between the droplet and its …

Fragment-Based Drug Discovery Of Sars-Cov-2 Therapeutics, Hannah Johnson '22

Student Publications & Research

During the COVID-19 pandemic, the usual drug development timeline has been substantially condensed. This shortened timeline aims to allow for a safe and effective therapy to be discovered as soon as possible as the number of global COVID cases rise. Moreover, the COVID Moonshot open-sourced initiative has allowed the development of a COVID antiviral to accelerate. After the published fragment screening on the main protease (MPro) of SARS-CoV2 yielded 66 fragment hits, a fragment (x0434) was selected to build novel compounds. SeeSAR was used to gather preliminary knowledge of the three-dimensional structure of the biomolecular targeted protein and selected fragment …

Pollution In Rainwater Harvesting: A Challenge For Sustainability And Resilience Of Urban Agriculture, Yang Deng

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Water plays a pivotal role in urban agriculture. Although rainwater harvesting (RWH) is viewed as a sustainable route for crop irrigation at an urban setting, rainwater contaminants challenge the RWH practices due to potential threats to the health of crops, soil, and human (i.e., farm workers and food consumers). This frontier review article first recognized principal pollutants of irrigation concern in harvested rainwater based on literature data and crop irrigation demands. Major traditional pollutants, likely exceeding irrigation quality criteria, include particles, some toxic metals (e.g., Cd, Cu, and Zn), certain synthetic organic chemicals (e.g., agrochemicals and polycyclic aromatic hydrocarbons), and …

Aqueous Wastewater Treatment With Aluminium Oxide, Silicon Dioxide And Alginite, Anifat Adenike Bankole

Theses

Wastewater, regardless of the source, has always found its way into the environment. If not treated it can pose a threat to the life of humans as well as aquatic organisms. In regard to the treatment of wastewater containing remnant organic dyes, the adsorption of these on recyclable sorbent materials such as alginite, alumina, and silica gel was evaluated. The main objective of this thesis is to evaluate the sorption process for dye tainted water specifically stemming from educational and research laboratories. Adsorption studies of the wastewater with sorbent materials were carried out under different experimental conditions. The study investigates …

College Of Natural Sciences Scholarship Brunch Program, November 6th 2021, College Of Natural Sciences

College of Natural Sciences Newsletters and Reports

This is the program for the first annual College of Natural Sciences Scholarship Brunch, held on November 6th, 2021 at McCrory Gardens.

College Of Natural Sciences Newsletter, November 2021, College Of Natural Sciences

College of Natural Sciences Newsletters and Reports

Volume 2, Issue 11

Page 1 Dean's Message
Page 2 Awards & Recognition
Page 3 Media Coverage of CNS
Page 4 2021 Day of Scholars
Page 5 Astronomy Outreach
Page 6 SDSU Faculty & Students Host American Society for Microbiology Annual Conference
Page 7 Scholarship Brunch
Page 8 Open PRAIRIE Data, SI Final Exam Review Sessions
Page 9 Aamlid Family Anatomy Lab Photos

Facile Synthesis Of Tertiary Amine Pendant Polymers By Cu0-Mediated Atrp Under Aqueous Conditions, Collin M. Britten, Kristen Lason, Keisha Walters

Chemical Engineering Faculty Publications and Presentations

Cu⁰-mediated atom transfer radical polymerization (ATRP) in aqueous media is extended to tertiary amine-pendant methacrylate polymers with poly([2-dimethylamino]ethyl methacrylate) (PDMAEMA) serving as a model polymer. By increasing the concentration of deactivating Cu^II species, reducing the reaction temperature, and increasing the supporting halide concentration to 1 M, polymers with well-defined molecular weight distributions (MWDs) are achieved in under 4 h. MWDs show good agreement with theoretical values, with polydispersity indices (Đ) as low as 1.14. Furthermore, this reaction system shows a remarkable tolerance to dissolved oxygen, with little to no deleterious effects observed for polymerizations run …

Bisindolylmaleimide Ix: A Novel Anti-Sars-Cov2 Agent Targeting Viral Main Protease 3clpro Demonstrated By Virtual Screening Pipeline And In-Vitro Validation Assays, Yash Gupta, Dawid Maciorowski, Samantha E. Zak, Krysten A. Jones, Rahul S. Kathayat, Saara-Anne Azizi, Raman Mathur, Catherine M. Pearce, David J. Ilc, Hamza Husein, Andrew S. Herbert, Ajay Bharti, Brijesh Rathi, Ravi Durvasula, Daniel P. Becker, Bryan C. Dickinson, John M. Dye, Prakasha Kempaiah

Chemistry: Faculty Publications and Other Works

SARS-CoV-2, the virus that causes COVID-19 consists of several enzymes with essential functions within its proteome. Here, we focused on repurposing approved and investigational drugs/compounds. We targeted seven proteins with enzymatic activities known to be essential at different stages of the viral cycle including PLpro, 3CLpro, RdRP, Helicase, ExoN, NendoU, and 2′-O-MT. For virtual screening, energy minimization of a crystal structure of the modeled protein was carried out using the Protein Preparation Wizard (Schrodinger LLC 2020-1). Following active site selection based on data mining and COACH predictions, we performed a high-throughput virtual screen of drugs and investigational molecules (n = …

Preparation And Evaluation Of Crocetin-Coated Biodegradable Polymer On Top Of Magnetite Nanoparticles For Their Anticancer Effects, Sulafa Saeed Abdelhalim

Theses

Liver cancer is still one of the leading causes of cancer-related deaths worldwide. This is due to many reasons including lack of effective drugs, late diagnosis of this type of cancer due to the overlapping of symptoms with many other liver diseases, and lack of effective screening tests. Targeted drug delivery systems offer many promising advantages compared to conventional chemotherapy. Targeted delivery will mitigate the bad side effects of chemotherapy such as drug resistance, low therapeutic value since the drug mostly will be administered through an IV affecting healthy and cancer cells alike, and that leads us to an important …

Molecular Mechanisms Underlying Enhanced Hemichannel Function Of A Cataract-Associated Cx50 Mutant, Jun-Jie Tong, Umair Khan, Bassam George Haddad, Peter J. Minogue, Eric C. Beyer, Vivian M. Berthoud, Steve L. Reichow, Lisa Ebihra

Chemistry Faculty Publications and Presentations

Connexin-50 (Cx50) is among the most frequently mutated genes associated with congenital cataracts. Although most of these disease-linked variants cause loss of function because of misfolding or aberrant trafficking, others directly alter channel properties. The mechanistic bases for such functional defects are mostly unknown. We investigated the functional and structural properties of a cataract-linked mutant, Cx50T39R (T39R), in the Xenopus oocyte system. T39R exhibited greatly enhanced hemichannel currents with altered voltage-gating properties compared to Cx50 and induced cell death. Coexpression of mutant T39R with wild-type Cx50 (to mimic the heterozygous state) resulted in hemichannel currents whose properties were indistinguishable from …

Synthesis Of Alkylthio Benzene Derivatives Via Simultaneous Diazotization And Nucleophilic Displacement, Abraham Alvarado, Juan D. Deleija, Jose J. Gutierrez

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Alkylthio benzene derivatives were effectively synthesized by simultaneous diazotization of aromatic amines and nucleophilic displacement. The method is fairly general and proceeds in moderate yields. Product yields were comparable regardless of steric hindrance of the thiol or of the functional group present in the starting material. The newly developed procedure allowed for the incorporation of a tertiary alkylthio group, which cannot be easily introduced otherwise. The products were characterized by 1H NMR and 13C NMR.

Understanding Hyperporphyrin Spectra: Tddft Calculations On Diprotonated Tetrakis(-Aminophenyl)Porphyrin., Jeanet Conradie, Carl C. Wamser, Abhik Ghosh

Chemistry Faculty Publications and Presentations

A detailed TDDFT study (with all-electron STO-TZ2P basis sets and the COSMO solvation model) has been carried out on the effect of diprotonation on the UV-vis-NIR spectra of free-base tetraphenylporphyrin and tetrakis(-aminophenyl)porphyrin. The diprotonated forms have been modeled as their bis-formate complexes, i.e., as so-called porphyrin diacids. The dramatic redshift of the Q-band of the TAPP diacid has been explained in terms of an elevated "a" HOMO and lowered LUMOs, both reflecting infusion of aminophenyl character into the otherwise classic Gouterman-type frontier MOs. The exercise has also yielded valuable information on the performance of different exchange-correlation functionals. Thus, the hybrid …

Colloidal Nanomaterial Surface Chemistry And Characterization Studied By Linear And Nonlinear Spectroscopy, Asela Sampath Dikkumbura

LSU Doctoral Dissertations

Recent studies have demonstrated the use of nanomaterials such as metallic nanoparticles, liposomes, and polymer microparticles for biomedical applications, encompassing the field of nanomedicine. For developing novel core-shell metallic nanoparticles with controlled surface morphology, the in situ growth dynamics of colloidal silver-gold core-shell (Ag@Au CS) nanoparticles (NPs) in water are monitored in a stepwise synthesis approach using time-dependent second harmonic generation (SHG) and extinction spectroscopy. Transmission electron microscopy images show that the CS NP surface morphology becomes more smooth and uniform as the reaction proceeds, corresponding to lower, stable SHG signals and narrower plasmonic spectra that are compared to finite-difference …

Electrochemical Synthesis Of P-(Β-Hydroxyethyl Sulfone) Aniline, Hao Guo, Dong-Fang Niu, Shuo-Zhen Hu, Xin-Sheng Zhang

Journal of Electrochemistry

Para-ester is the most important intermediate for the preparation of ethylene sulfone type reactive dyes, which is usually used in the dyeing of cellulose fibers and synthetic fibers. P-(β-hydroxyethyl sulfone) aniline is an important intermediate for the synthesis of para-ester. In this paper, p-(β-hydroxyethyl sulfone) aniline was prepared by electrochemical method, having the advantages of simple process, mild reaction condition, less environmental pollution, easy reaction control and so on. It has strong development potential and industrial application prospect. The electrochemical reduction of p-nitrophenyl-β-hydroxyethyl sulfone on a lead plate electrode to prepare p-(β-hydroxyethyl …

Numerical Study On The Influences Of Flow Channel And Rib Width Ratio On The Performance Of Gas Diffusion Layer, Rong-Qiang Wei, Shi-An Li, Yi-Hui Liu, Zhi Yang, Qiu-Wan Shen, Guo-Gang Yang

Journal of Electrochemistry

Proton exchange membrane fuel cell (PEMFC) has the advantages of low noise, high power density, and zero emission. It is widely used in ships, automobiles, aviation and other fields. PEMFC is composed of bipolar plate (BP), gas diffusion layer (GDL), catalytic layer (CL) and proton exchange membrane (PEM). GDL has a supporting catalytic layer and proton exchange membrane, which provides gas diffusion for the reaction and a channel for the reaction to produce water, and transmits the anodic oxidation reaction. In the assembly of fuel cells, a certain assembly pressure is required to ensure air-tightness and effective conductivity. The assembly …

Mathematical Expression And Quantitative Analysis Of Impedance Spectrum On The Interface Of Glassy Carbon Electrode, Lei Cheng, Pu-Xuan Yan, You-Jun Fan, Hua-Hong Zou, Hong Liang

Journal of Electrochemistry

Glassy carbon electrode (GCE) is a common basic electrode for various electrochemical sensors, and the detection properties are determined by its interfacial characteristics. In this paper, we established an equivalent circuit including electrolyte resistance (R_el), charge transport resistance (R_ct), diffusion impedance (R_di, C_di), electrochemical (oxidation/reduction) reaction impedance (R_R, C_R), surface adsorption impedance (R_ads , C_ads), double-layer capacitance (C_DL), and derived the mathematical expression for the equivalent circuit. The R_el and C_DL are contributed by inactive …

Preparation Of Modified Titanium Based Pbo2 Electrode And Its Rapid Detection Of Cod, Qi Sun, Yan-He Han, Xiao-Lu Fu

Journal of Electrochemistry

In the traditional Ti/β-PbO₂ electrode, the crystal lattice difference between β-PbO₂ and Ti matrix is large, and the prepared electrode is easy to fall off and has a short service life. It needs to be modified in actual use. Based on the advantages of α-PbO₂ material and Ag material in terms of adhesion and conductivity, respectively, the above two materials are selected as the intermediate layer of Ti/β-PbO₂ electrode to improve electrode performance. In this paper, by preparing Ti/α/β-PbO₂ and Ti/Ag/β-PbO₂ electrodes …

Pair Distribution Function Analysis And Electrochemical Performance Of Mesoporous Carbon Nanomaterials Synthesized Through Koh And Zncl2 Activation, Talam E. Kibona, Sarah Frisco, Maxwell W. Terban

Tanzania Journal of Science

Mesoporous carbon has been synthesized by activating carbonized biogas slurry residues with ZnCl2 and KOH simultaneously. The carbon to activating agent mass ratios were kept at 1:4, while the ZnCl2 to KOH mass ratio varied from 4:0, 3:1, 2:2, 1:3, to 0:4. The highest BET specific surface area of 361 m2 g-1, micropore surface area of 231 m2 g‒1, mesopore surface area of 125 m2 g‒1, and total pore volume of 0.23 cm3 g‒1 which amounted to 78% mesopore content, were obtained for the sample with 3:1 ZnCl2 to KOH mass ratio. Scanning electron microscope (SEM) images were acquired to …

Fundamentals Of Electrochemical Impedance Spectroscopy For Macrohomogeneous Porous Electrodes, Xiang Li, Qiu-An Huang, Wei-Heng Li, Yu-Xuan Bai, Jia Wang, Yang Liu, Yu-Feng Zhao, Juan Wang, Jiu-Jun Zhang

Journal of Electrochemistry

Electrochemical impedance spectroscopy (EIS) can be used to diagnose charge transfer reactions and mass transport in porous electrodes. The charge transfer reactions include interfacial charge accumulation and charge conduction as well as electrochemical reaction. In this paper, the complex phasor method is developed under the macrohomogeneous assumption to build an impedance model of porous electrodes for clarifying several vague expressions in the traditional approaches. The following researches are carried out: (1) Identifying characteristic parameters for the porous electrodes, including electrode electronic conductivity σ₁, electrolyte ionic conductivity σ₂, interface charge transfer conductivity g_ct, unit area …

Janus-Tinbco2 For Hydrogen Evolution Reaction With High Conductivity And Catalytic Activity, Li-Li Xu, Dong-Yan Ren, Xiao-Feng Zhao, Yong Yi

Journal of Electrochemistry

Exploring the potential hydrogen evolution reaction (HER) catalysts with the high activity and high conductivity has always been a hot spot in the research of renewable energy development. Ti₂C, as one of the 2D-MXene, has excellent properties relating to many active sites, mechanical stability, conductivity, etc., and has become a potential HER catalyst. However, the modification of the surface of Ti₂C by terminal O will reduce the conductivity, thereby limiting the transport of electrons between the valence band and the conduction band. In this study, an electric double layer Janus-TiNbCO₂ was constructed by Nb doping. …

Application Of Ti/Ruo2-Iro2-Sno2-Sb2O5 Anode In Rural Drinking Water Disinfection, Jing-Ru Guo, Xue-Jiao Zhang, Shuai Liao, Xue-Ming Chen

Journal of Electrochemistry

Sodium hypochlorite disinfection has many advantages, including reliable operation, low cost, easily available raw materials. It is, therefore, suitable for disinfection of drinking water in remote rural areas. The service life and chlorine evolution efficiency of the anode are the main factors restricting the performance of the sodium hypochlorite generator. The special conditions of frequent shutdown and low electrolyte concentration in the rural drinking water application also put forward high requirements on the performance of the anode. In this study, Ti/RuO₂-IrO₂-SnO₂-Sb₂O₅,a new-type and efficient chlorine evolution anode, was prepared by …

Study On Improving The Production Of Ammonium Persulfate By Ion Membrane Electrolysis, Yi-Hang Qu, Min Cui, Cong Zhang, Chong Li, Peng Li, Ju-Jie Ren

Journal of Electrochemistry

In china, the production of ammonium persulfate in factories mostly adopts the electrolysis method with simple process and high purity. However, there exists the problem of high energy consumption in the electrolysis process, which restricts the further development of ammonium persulfate in many fields. Aiming at this phenomenon, the equipment and technology to produce ammonium persulfate using electrolysis were designed and studied in order to reduce energy consumption. A new type of zero-pole distance and ion-exchange membrane industrial electrolytic cell was provided for the electrolysis production of ammonium persulfate. An ion-exchange membrane was used to separate the electrolytic cell into …

Synthesis Of Nickel Phosphide/Nitrogen Phosphorus Co-Doped Carbon And Its Application In Lithium Ion Batteries, Jian Hu, Yan-Shuang Meng, Qian-Ru Hu

Journal of Electrochemistry

In recent years, the nickel-based phosphide has drawn great attention because of its low intercalation/deintercalation platform and lower polarization compared to sulfides and oxides as anodes for next-generation high-energy lithium-ion batteries. The Ni₂P anode can deliver high theoretical specific capacity of 542 mAh·g^-1, but it subject to a conversion reaction mechanism, which make them unsuitable for commercial applications. The agglomeration of Ni₂P nanoparticles during material fabrication and the structural deterioration of electrode associated with large volume change during charge-discharge process lead to poor cycle stability and low utilization of active materials. Meanwhile, the low …

Performance And Mechanism Of PtXCuY/C Electrocatalyst For Methanol Oxidation, Jia Tang, Xiao-Ming Zhang, Shan-Sheng Yu, Su-Li Wang, Gong-Quan Sun

Journal of Electrochemistry

Direct methanol fuel cell (DMFC), which directly converts the chemical energy of methanol fuel into electrical energy, has the advantages of high energy conversion efficiency, environmental friendliness, and abundance of fuel sources. DMFC is considered as the promising substitutes in the field of portable devices, military applications, and stationary power stations, while the broad application is severely hindered by the sluggish kinetic of methanol oxidation reaction (MOR) in the anode and the high cost of platinum (Pt)-based anodic electrocatalysts. Herein, a series of carbon supported Pt_xCu_y (Pt_xCu_y/C) binary metal electrocatalysts, featured with high …

Effect Of Alkyl Chain Length Of Symmetrical Quaternary Ammonium Hydroxide On Oxalic Acid Electroreduction Reaction, Bo Huang, Xin-Sheng Zhang, Dong-Fang Niu, Shuo-Zhen Hu

Journal of Electrochemistry

Glyoxylic acid with the dual characteristics of acid and aldehyde is an important chemical raw material and organic synthesis intermediate, which is extensively used in the perfumery, pharmaceutical and fine chemical industries. A family of symmetric quaternary ammonium hydroxides (QAHs) with different alkyl chain lengths was used as the additives in generating glyoxylic acid from oxalic acid electroreduction reaction (OAER). The effects of alkyl chain length on OAER and the corresponding side reaction, i.e., hydrogen evolution reaction (HER), were investigated. Linear sweep voltammetric (LSV) results showed that the adsorption of the additives suppressed more on the HER than that on …